From Table 7.4a, it is apparent that identifying the corrosivity category for the design situation is key to obtaining an accurate life to first maintenance. The environment in which the material will be located must be carefully assessed to determine which of these categories is applicable for the location in question.
The LTFM figures presented in the table above are similar to those documented by the galvanised steel suppliers for the different locations (shown below):
Dry & Unpolluted: 20 – 50 years
(Typical for most common applications – offices, warehouses, hospitals, airports)
Suburban & Rural: 5 – 10 years
Coastal: 2 – 5 years
Industrial and Urban: 2 – 5 years